Though Instagram attempts to block such search results and direct teens to helplines, it has never notified parents about their children's activity. Parents will receive the alert via an app notification and a separate email, text, or WhatsApp message, depending on the contact information they provided.
At its core, a stream is just a sequence of data that arrives over time. You don't have all of it at once. You process it incrementally as it becomes available.
，这一点在同城约会中也有详细论述
Овечкин продлил безголевую серию в составе Вашингтона09:40
（二）业务之间具有明显的主附关系。主要业务居于主体地位，体现交易的实质和目的；附属业务是主要业务的必要补充，并以主要业务的发生为前提。